Omar Suleiman, the Egyptian intelligence chief under the regime of Hosni Mubarak, died in the U.S. during medical examinations, a relative said on Thursday. He also served for a short period as the vice president of Mubarak before the regime fell in February 2011. He was 76 years old.

"He was healthy. His death occurred suddenly while he was passing medical examinations in Cleveland," said one of his assistants, Hussein Kamal, without giving the cause of death.

The spy-diplomat had applied for this year's first presidential election in the post-Mubarak era, but had been dismissed by the election commission who said he had not gathered enough signatures for his candidacy.

Loyal confidant of Mubarak, Suleiman took the post of head of General Intelligence Services (EGIS) in 1993 and played a leading diplomatic role in relations between Egypt and Israel, the Palestinian Authority and Hamas, and the United States.

He had also been at the forefront of the struggle in the 1990s against armed Islamist groups.